the firmware is different for each drive all the v5.2 (a,b,c,d) Im pretty sure thats just for sammy drives.

At current if my memory serves me correctly v.2.3 revision 2 maximus garopa stealth is the latest for hitachi?

Stealth means that the back is undectable its for future use. Baically if we dont stealth our games it means that possibly in the future M$ may find a way to detect them. So if we stealth them now itll save up bruning all those valuable backups again